Are bioplastics a silver bullet solution?

Are bioplastics the silver bullet solution we’ve been waiting for?

Plastic is a global catastrophe.

Imagine the effect two thousand garbage trucks full of plastic tipped into the world’s waterways daily is having on our aquatic ecosystems.

Plastic, as we know it today, originated from plant-based technology. Before petrol-based plastics took over, plastic was made from plant-based cellulose (celluloid) and other plant products. Ford even produced a car using components made from soybean-derived bioplastics.

Petrol-based plastic eventually took over from bioplastics due to its superior versatility and easier production.

What are bioplastics?

Looking, feeling and acting like conventional plastic, bioplastic is made from plants, not petrol-based chemicals. In general, bioplastics produce two-thirds to three-quarters less carbon and emit less greenhouse gases. They also don’t rely on fossil fuels.

As an interesting experiment for the kids, you can make a form of bioplastic in your kitchen using cornstarch, glycerol and vinegar.

Bioplastic technology is being embraced by huge companies like Coca-Cola, which are producing products indistinguishable from conventional plastic. Even so, bioplastic still makes up only about 1 percent of all plastics being used but there are signs that demand is growing.

So, what’s the catch?

Although bioplastics are derived from plants like potatoes, sugarcane and casava, not all bioplastics are biodegradable. Just because it is derived from plants doesn’t mean bioplastic will turn back into soil. Only 55 percent of bioplastics are biodegradable and even those require composting. This means that the problems we experience with traditional plastic, like clogging up landfills and waterways, are not remedied by bioplastics.

Bioplastic is also a significant drain on resources. To use bioplastics as a substitute for petrochemical plastic packaging globally, would require 54 per cent of the current global production of corn, 12 times the current global production of castor beans, 388.8 billion m³ of water and 0.8 per cent of current global roundwood production. All this would require around 61 million hectares of land (larger than the total area of France). In other words, just not realistic.

Bioplastics have their place in the circular economy and are environmentally superior to conventional plastic, but they are not the silver bullet we anticipated. At present, the only remedy to reducing the negative impact of plastic on our environment is to choose 100 per cent renewable plastic alternatives.

Recycling plastic

Reusing plastic already in circulation through recycling reduces:

•  Demand for raw materials and fossil fuel
• CO2 emissions
• Strain on landfills.

Plastics that can be recycled include type 1 PET – Polyethylene Terephthalate, type 2 HDPE – High-Density Polyethylene, PVC – Polyvinyl Chloride, type 4 LDPE – Low-Density Polyethylene or type 5 PP – Polypropylene.

Unfortunately, recycling plastic is challenging. Most recyclers refuse to take plastic contaminated with dirt, dust or other residue. Cleaning plastic waste can be prohibitively costly and time-consuming for businesses.

Soft plastics, such as those used in bubble wrap, plastic wrappers, foam drinking cups and bread bags, cannot be recycled, or recycling options are limited.

Researchers are experimenting with fungi, algae and black fly larvae to degrade plastics and edible plastics are also under investigation. The results are encouraging. Trials at the University of Sydney found the fungi Aspergillus terreus and Engyodontium album broke down UV light-treated polypropylene, reducing the plastic by 21 per cent over 30 days of incubation, and by 25-27 per cent over 90 days.

If we must rely on plastic as a universal storage and packaging option, a solution befitting the scale of the problem is vital. We await the results of the research with bated breath…